* Rename 'rtl' to 'isRTL' and use DOM to compute its value.
* Document code with JSDuck similar to other extensions.
* Remove unused 'prevElement' property. Not used in Vector
nor anywhere else in Wikimedia Git.
* Make 'boundEvent' property private. Not used anywhere in
Wikimedia Git outside this file.
* Simplify 'instances' tracking.
The jQuery object stored in this property wasn't used beyond
calling each(). Convert to a plain array.
Preserve and re-use the jQuery object first created
by collapsibleTabs().
* Simplify calculateTabDistance() by using getElementById() and
getBoundingClientRect(). Its support includes IE 5.
The "new" version (since Firefox 3.5 and IE 9) also includes
'height' and 'width' properties and is supported in all
browsers supported by the MediaWiki 1.28 startup feature test.
This helps avoid code in offset() and width(), which is fairly
expensive in jQuery 1.x.
* moveToCollapsed()
- Remove redundant jQuery object creation (only caller passes a
jQuery object already).
- Remove redundant re-receiving of expContainerSettings inside
the animate() callback. Already in the main scope.
Relates to a bunch of patches that work around a problem
caused by use of remove() instead of detach() in an earlier
version of the code. Which was only a problem because the
other settings object was also not used from the main scope.
(See pre-Gerrit commits 1f93310e and e7900807.)
Change-Id: I48d542580d767df2d17ce4c6668e9e233a0f7902
